1. Field of the Invention
The invention generally relates to an adjustable parallel machine tool. In particular, it relates to a machine tool employing opposing slideable wedges which is used singularly or in plurality as a precise height adjustment locating device under an object to be machined on such machines as a Bridgeport mill, a horizontal mill, or any other conventional machine where precise measurement of vertical height is a necessary requirement.
2. Description of Prior Art
Most machinists have a ready supply of hardened steel oblongs or parallels of various lengths, widths and heights. Such parallels and oblongs have been ground so that at least two sides are absolutely and precisely parallel, and have a specific dimension. When the machinist is in the preparation of setting up an object to be milled, routed or machined in any mode, he usually does not have the proper size of a particular vertical height of parallel or oblong.
Accordingly, to achieve a desired vertical height location beneath an object, the machinist must stack a plurality of parallels, one above the other, of various thicknesses, employing a trial and error type of method to reach a particular and final vertical height location by using a variety of thin metallic pieces known as "shim stock." Consequently, significant amounts of the machinist's time are involved in such operations and the cost becomes considerable and expensive. For example, one machinist set-up time on one machine, per 8-hour shift, may be as high as three hours per shift. A combined set-up time on 15 various machines may total 30 to 40 hours per 8-hour shift. On a monthly or annual basis, the set-up time is highly magnified, such a time element considered down time or nonproductive machining time.
In addition, when machining operations are not completed on one 8-hour shift, or for several 8-hour shifts on a complex object, the machinist must often remove his project at the end of the shift or day so that the machine may be stripped down and cleaned. This results in the repetition of set-up procedures for the machining during the following day. Thus, multiple set-up times reach a significant magnitude.